Yarns comprising two or more bundles of metal fibres are known. Such yarns are e.g. applied in vehicle seat heating systems or heatable textiles. In these applications, the yarns are used as an electrical resistance and provided with an electric current to obtain the required heating effect. Other applications of such yarns include the use as anti-static brushes, the use as leadwire for electrodes or as an electrical conductor for power and or signals.
In many of these applications, the yarns are subjected to different stress and/or strain conditions. In particular, the yarns may be repeatedly loaded under tensile and/or bending or torsion stresses. When repeatedly subjected to such stresses, metal fibers in the yarn may break, eventually resulting in the failure of the yarn.